JPH0668775A - Tripping device - Google Patents

Abstract

PURPOSE:To enable tripping even if a load of an operation mechanism is increased to a degree exceeding attraction force in a normal tripping position. CONSTITUTION:A tripping device is constituted in such a way that two iron cores 22 and 24 are made movable, and force applied to the second iron core 24 is set larger than a normal load P1, and the force is set smaller than attraction force of the iron core 22 in a tripping position, and when a load is increased to P2, the second iron core 24 is attracted to the first iron core 22, and the attraction force becomes F2 (>=P), and tripping becomes possible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trip device used for a switch such as a circuit breaker.

[0002]

2. Description of the Related Art FIG. 3 is a sectional view showing a conventional voltage trip device, in which 1 is a yoke, 2 is a movable iron core, and 3 is a movable core.
Is a nut attached to the threaded portion at the tip of the movable iron core 2, and serves as a downward stopper of the movable iron core 2. 4 is a fixed iron core,
It is fixed by being sandwiched between the sleeve 5 and the yoke 1. Reference numeral 6 denotes a compression coil spring, which applies a downward force to the movable iron core 2. A magnetic shield 7 is in contact with the movable core by a spring 6. 8 is a coil. A pressing plate 9 for preventing the sleeve 5 from coming off is fixed to the yoke 1 by, for example, a screw.

Next, the operation will be described. When the coil 8 is excited, the movable iron core 2 is attracted to the fixed iron core 4, and the stroke (not shown) of the tripping mechanism portion of the operation mechanism connected to the movable iron core 2 is tripped at the stroke L1. After that, the movable iron core is attracted, and the magnetic shield plate 7 rises until it contacts the fixed iron core 4. This entire stroke is L0. When the excitation is cut off, the movable iron core 2 is pushed down by the spring 6, and the nut 3 as a stopper hits the upper end of the fixed iron core 4 and stops.

[0004]

The conventional trip device is constructed as described above, and the gap G1 between the fixed iron core 4 and the movable iron core 2 at the stroke L1 by which the latch is tripped is always constant (G1). = L0-L1 = constant), the suction force when the latch is pulled out is always constant. Therefore, the force P1 required for tripping the latch increases for some reason, and the suction force F1
If it exceeds, it may become impossible to trip.

The present invention has been made to solve the above problems, and an object thereof is to obtain a trip device which can increase the suction force even when the required trip force increases. .

[0006]

In a trip device according to the present invention, a fixed iron core of a conventional device is used as a second movable iron core, and the tripping device according to the attraction force F1 of the iron core at a stroke L1 when the latch is tripped. A reset spring for the second movable iron core, which sets the applied force, is provided.

[0007]

In the trip device according to the present invention, when a large load is applied to the first movable iron core for some reason,
The second movable iron core is attracted to the first movable iron core side, and the gap between the two becomes narrower, so the attraction force to the first movable iron core increases more than in normal times, and it is possible to respond to an increase in load. And perform the tripping operation.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. In FIG. 1, 21 is a yoke, 22 is a first iron core, and 3
Is a nut attached to the threaded portion of the tip of the first iron core, and serves as a downward stopper of the first iron core 22. Reference numeral 24 is a second iron core, 30 is a spring that applies an upward force to the second iron core 24, 29 is a holding plate of the second iron core 24, and 26 is a reset spring of the first iron core 22. A sleeve 25 serves as a guide for the first iron core 22 and also as a downward stopper for the second iron core 24. 7
Is a magnetic shield and is in contact with the first iron core 22 by a spring 26. 8 is a coil. Also, the first iron core 22 has a hole 22a.
Is provided and is connected to a latch (not shown) of the operating mechanism by using the hole 22a, for example, by a pin or the like.
1 and 2, L0 is the total stroke of the first iron core 22, L1 is the trip position of the latch, R is the movable stroke of the second iron core 24, Pi is the load force of the latch, and F is the distance between the iron cores. Fi is the suction force at the stroke Li.
Gi represents the gap between the iron cores. The force of the spring 30 is Wi.

Next, the operation will be described with reference to FIGS. First, when the load P1 of the latch is normal, when the coil 8 is excited, the first iron core 22 is attracted and the stroke L
At 1 the latch is tripped. At this time, the gap G1 between the iron cores is G1 = L0-L1, and the attraction force F1 is larger than the load P1 of the latch (F1> P1). Also, the force W0 of the spring 30
Is set to be larger than P1 and smaller than F1. That is,
There is a relationship of F1>W1> P1. Next, assume that the load of the latch increases to P2 (> F1) for some reason. In the conventional device, since the second iron core is fixed, the attraction force F1 does not exceed the load P2, so the latch is not tripped. In the present invention, the second iron core 24 is movable, and F1
> W1, so in this case, the second iron core 24 is the first
When the suction force F2 exceeds the load P2 by being attracted to the iron core 22 of the first iron core 22, the first iron core 22 moves upward again, the latch is tripped, and the link system of the operating mechanism becomes free. , For example, the circuit breaker trips. The spring
The force of 26 is considerably smaller than that of F, P and W, so it can be ignored.

In the above embodiment, the springs 26 and 30 are composed of compression coil springs, but they may be composed of other tension springs or torsion springs. In addition, although the voltage trip device has been described in the above embodiment, a current trip device may be used, and the same effect as that of the above embodiment is obtained.

[0011]

As described above, according to the present invention, by making the conventional fixed iron core movable, the latch can be easily tripped even if the load of the latch of the operating mechanism increases. Since it is configured, there is an effect that a highly reliable device can be obtained.

Further, the device can be downsized by reducing the force of the spring so that the second iron core can be moved even in the normal case and the tripping can be performed with a small gap.

[Brief description of drawings]

FIG. 1 is a sectional side view showing a voltage trip device according to an embodiment of the present invention.

FIG. 2 is a graph showing a force relationship of the embodiment of the present invention.

FIG. 3 is a cross-sectional side view showing a conventional voltage trip device.

[Explanation of symbols]

 3 nut 8 coil 21 yoke 22 first iron core 24 second iron core 25 sleeve 26 spring 30 spring

Claims (1)

[Claims] 1. A coil for generating an electromagnetic force by excitation, a yoke surrounding the coil, a coil surrounding the coil, a magnetic path of the coil and the yoke, which is attracted and moved by the electromagnetic force of the coil to operate a tripping operation mechanism. No. 1 iron core, and a second iron core also arranged in the magnetic path so as to face the first iron core at a distance from the first magnetic core. The second iron core has a predetermined direction in the moving direction of the first iron core. A tripping device, which is movably supported in a range and is biased by a spring in a direction away from the first iron core.